The present invention is directed to an anchoring unit for securing fastening members to a support or receiving material containing internal open spaces with a hardenable mass securing the anchoring unit to the structure. The anchoring unit includes a screen-type sleeve with openings through it for the passage of the hardenable material or mass and an insert sleeve to be placed into the screen-type sleeve. The insert sleeve has an axially extending passage or bore for receiving the fastening member, with the fastening member being inserted into the trailing end of the insert sleeve.
Anchoring units formed of a screen-type sleeve and an insert sleeve and anchorable by a hardenable material or mass in hollow masonry and the like are known, note the brochure "Applications and Products 1985" of German Hilti GmbH. The screen-type sleeve, formed of a wire mesh, serves to distribute the hardenable mass into the open spaces in the structure, while the insert sleeve provides a detachable connection with a fastening member not directly secured by the hardenable mass. The transmission of the retaining force is achieved in this anchoring unit predominately by a positive locking connection afforded by the hardenable mass.